Lincus curvatus, Campos, Luiz Alexandre & Roell, Talita, 2017

Campos, Luiz Alexandre & Roell, Talita, 2017, Description of four new species of Ochlerini from South America (Hemiptera: Pentatomidae: Discocephalinae), Zootaxa 4236 (3), pp. 507-520 : 510-515

publication ID	https://doi.org/ 10.11646/zootaxa.4236.3.5
publication LSID	lsid:zoobank.org:pub:23A6A545-BE2C-42B5-ACB9-48B10A4879AA
DOI	https://doi.org/10.5281/zenodo.6018950
persistent identifier	https://treatment.plazi.org/id/1E5275F3-F96E-4379-923D-B3FE8ED96D97
taxon LSID	lsid:zoobank.org:act:1E5275F3-F96E-4379-923D-B3FE8ED96D97
treatment provided by	Plazi
scientific name	Lincus curvatus
status	sp. nov.

Treatment

Lincus curvatus sp. nov.

( Figs. 2–6 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 )

Etymology. The epithet refers to the curved male proctiger; Latin: curvatus , bend, bow, crook.

Type locality. Ecuador, Orellana, El Coca (coordinates -0.2861, -77.1016).

Holotype male. Labels: Ecuador, Orellana, El Coca, Palmar del Rio , 1-15/X/2015, R. Asipuela col., on OxG hybrids ( Elaeis oleifera x Elaeis guineensis ) ( DZUP)

Paratypes: 7 females, 5 males. Same data as holotype (2 females and 1 male DZUP; 5 females and 4 males UFRG).

Description. Body oval, dark brown. Head subrectangular, wider than long; punctures confluent forming wrinkles, denser between eyes; mandibular plates reflexed, little longer than clypeus and converging towards the apex, not touching each other before clypeus. Width of each eye equal to half the interocular width. Ocelli placed close to the lateral margins of head and posterior to an imaginary line connecting the posterior limit of eyes. Antennae with five antennomeres bearing thin setae, denser on fourth and fifth antennomeres; dark brown except for the base of fifth antennomere yellowish. Proportion of antennomeres: I<II<III<IV<V. Antennal tubercles visible from above, acute apically. Labium long arising posterior to an imaginary line connecting the anterior margins of eyes, reaching the sixth abdominal segment. Proportion of labium segments: I<II>III>IV. Labrum sinuous, bent frontwards.

Pronotum trapezoidal, wider than long at midline; punctures confluent, forming wrinkles, cicatrices with a median low tubercle. Anterior margin concave, anterolateral margins sinuous, reflexed and emarginated at humeral angles. Anterolateral pronotal margins expanded in obtuse angle posterior to pronotal lobes. Pronotal lobes spatulate, rounded, juxtaposed to posterior margin of eyes. Humeral angles not produced. Scutellum longer than wide, surpassing imaginary line connecting middle of each connexival segment V; punctures denser on disc, forming wrinkles; subtle yellowish spot at middle of anterior margin. Frenal margins longer than postfrenal margins. Corium longer than scutellum, reaching connexival segment VI, punctures denser than on scutellum, not forming wrinkles; subtle yellowish spot at apex of radial vein; membrane not surpassing the apex of abdomen. Membrane of corium arcuate cut in males. Pro- and metasternum flat, mesosternum carinate. Pro-, meso-, and metapleura sparsely punctured, metapleural evaporatorium extending less than half way to lateral margin of metapleuron. Peritreme spout-shaped. Tibiae sulcate dorsally and laterally, bearing lateral and ventral setae, these denser at apex. Third metatarsomere dorsally concave in males and females.

Abdomen ventrally convex at midline, thinly punctured; tricobothria lateral to imaginary line connecting lateral margin of spiracles.

Male. Membrane of corium arcuate cut ( Fig. 6 View FIGURE 6 ). Measurements (n=6): head length 1.74 ± 0.67 (1.70–1.90); width 2.07 ± 0.07 (1.94–2.14); interocular distance 1.06 ± 0.04 (1.00–1.10); pronotum length 2.41 ± 0.13 (2.20– 2.60); width 5.10 ± 0.06 (5.04–5.16); scutellum length 3.73 ± 0.35 (3.07–4.09); width 3.15; length of antennomeres: I 0.70 ± 0.00 (0.70–0.70), II 0.76 ± 0.05 (0.70–0.80), III 0.93 ± 0.05 (0.90–1.00), IV 1.33 ± 0.08 (1.20–1.40); V 1.67 ± 0.08 (1.60–1.80); length of labium segments: I 1.18 ± 0.14 (0.93–1.24), II 2.09 ± 0.09 (2.01– 2.17), III 1.72 ± 0.09 (1.64–1.86), IV 1.53 ± 0.10 (1.33–1.65); length of abdomen 4.88 ± 0.26 (4.41–5.04); width 5.86 ± 0.15 (5.67–5.99); total length 9.88 ± 0.20 (9.50–10.00).

Genitalia. Pygophore. Dorsal rim sinuous, projected mesially over base of segment X ( Fig. 2 View FIGURE 2 E, dr); lateral margins bearing setae. Posterolateral angles ( Figs. 2 View FIGURE 2 E, F, pa) rounded, with two dorsal laminar projections from the superior layer of ventral rim, bordered in black ( Fig. 2 View FIGURE 2 E, p2, p1): the first lateral, triangular in dorsal view placed near the distal margin of the posterolateral angle ( Fig. 2 View FIGURE 2 E, p2), and the second mesial, triangular in posterior view. This second projection continues ventrally to a third one, in the shape of an arched carina converging to the inferior layer of ventral rim ( Fig. 2 View FIGURE 2 G, p3). Ventral rim V-shaped ( Fig. 2 View FIGURE 2 F, vr), bearing setae. Parameres small, trapezoid ( Fig. 3 View FIGURE 3 E–H), covered by segment X. Segment X quadrangular and membranous at base, projected posteriorly and ventrad in cylinder, spatulate with rounded expansion at apex. The segment X curves to the right ( Fig. 2 View FIGURE 2 E–G). Phallus double drop shaped in dorsal view ( Fig. 3 View FIGURE 3 A); phallotheca strongly convex dorsally, limit between phallotheca and vesica tenuous ( Fig. 3 View FIGURE 3 A–D, ph); vesica expanded dorsodistally into a scimitar blade-shape ( Fig. 3 View FIGURE 3 C, v), in apposition to the tubular, sclerotized ductus seminis distalis ( Fig. 3 View FIGURE 3 C, ds). Secondary gonopore round.

Female. Measurements (n=7): head length 1.86 ± 0.04 (1.80–1.92); width 2.12 ± 0.07 (2.06–2.20); interocular distance 1.10 ± 0.11 (1.00 – 1.10); pronotum length 2.60 ± 0.16 (2.50–2.88); width 5.35 ± 0.19 (5.04–5.54); scutellum length 4.14 ± 0.09 (4.05–4.28); width 3.24 ± 0.09 (3.15–3.34); length of antennomeres: I 0.70 ± 0.01 (0.68–0.74), II 0.76 ± 0.07 (0.66–0.80), III 0.97 ± 0.09 (0.9–1.1), IV 1.32 ± 0.09 (1.20–1.40), V 1.78 ± 0.12 (1.60– 1.90); length of labium segments: I 1.24 ± 0.00 (1.24–1.24), II 2.17 ± 0.14 (2.01–2.35); III 1.78 ± 0.09 (1.70–1.86), IV 1.64 ± 0.04 (1.60–1.70); length of abdomen 5.75 ± 0.19 (5.54–5.92); width 6.22 ± 0.15 (6.11–6.4); total length 10.68 ± 0.80 (10.00–10.75).

Genitalia. Genital plates sparsely punctured; gonocoxites VIII and laterotergites IX wrinkled ( Fig. 4 View FIGURE 4 D, gcVIII, laIX). Gonocoxites VIII subtriangular, longer than wide, sutural margins straight, juxtaposed, posterior margins convex ( Fig. 4 View FIGURE 4 D, gcVIII). Laterotergites VIII trapezoid, wider than long, mesial and posterior margins subrectilinear ( Fig. 4 View FIGURE 4 D, laVIII). Exposed portion of gonocoxites IX lozenge, small ( Fig. 4 View FIGURE 4 D, gcIX). Exposed portion of laterotergites IX oval, not attaining the band uniting laterotergites VIII, mesial margins juxtaposed covering segment X ( Fig. 4 View FIGURE 4 D, laIX). Gonocoxites IX v-shaped ( Fig. 5 View FIGURE 5 A, C, gcIX), large and strongly convex. Gonapophyses IX weakly sclerotized, bent posteriorly ( Fig. 5 View FIGURE 5 A, C, gpIX), lateral portion rugose and bearing conical projections ( Fig. 5 View FIGURE 5 A, C, cp). Ring sclerites absent. Secondary thickenings of gonapophyses IX large, located medially on folds of gonapophyses IX. Thickening of vaginal intima broadly ogival, wider than long ( Figs. 5 View FIGURE 5 A, C, vi). Orificium receptaculi located on apex of vaginal intima ( Fig. 5 View FIGURE 5 A, C, or). Vesicular area of the ductus receptaculi about five or six times longer than the combined length of pars intermedialis and capsula seminalis; median duct ( Fig. 5 View FIGURE 5 A, md) fusiform at proximal end. Pars intermedialis twice the length of capsula seminalis ( Fig. 5 View FIGURE 5 A, B, pi, cs). Capsula seminalis globose, bearing three wide processes ( Fig. 5 View FIGURE 5 A, C, cs). Anterior (= distal) annular ridge directed to pars intermedialis; posterior (= proximal) annular ridge perpendicular to pars intermedialis.

Comments. Lincus curvatus is described in Lincus based on the overall body shape, the shape of head and pronotum, the presence of anterolateral pronotal lobes, and the structure of the genitalia in both sexes. In the key for the species of Lincus by Rolston (1983) the new species keys either to Lincus lamelliger Breddin for specimens with short pronotal lobes ( Fig. 2 View FIGURE 2 A, D), or to Lincus subuliger Breddin for specimens with long pronotal lobes ( Fig. 4 View FIGURE 4 A). These species, L. lamelliger and L. subuliger , are in the “big-eyed” informal group of species (sensu Rolston, 1983), characterized by the width of each eye equal or greater than one-half of the interocular width, as also seen in the new species. Also within the “big-eyed” group, the gonocoxites VIII of L. curvatus resemble Lincus styliger Breddin , the pygophore and phallus are similar to Lincus laminatus Rolston , while the segment X of male well projected beyond the posterior margin of pygophore and broadly expanded at apex resembles Lincus subuliger Breddin. L. curvatus can be readily distinguished by the dark body color, the shape and proportions of the female genital plates, the long mesial laminar projection in the superior layer of ventral rim of pygophore, and the curved segment X of males. The shape of the hemelytral membrane in males of L. curvatus is also a distinctive feature, and although this kind of sexual dimorphism has never been described for other species of Lincus, we observed similar modifications in males of Lincus lobuliger Breddin and Lincus securiger Breddin. Further morphological studies are needed to clarify whether wing dimorphism occurs in other species of Lincus.

Note: all specimens of Lincus curvatus sp. nov. were collected on oil palms (OxG hybrids, Elaeis oleifera x Elaeis guineensis ) affected by the lethal wilt (marchitez sorpresiva) disease.